A. Field of the Invention
This invention relates to the field of wireless telecommunications. More particularly, this invention relates to a wireless intelligent personal server that receives data transmitted over a wireless communications channel and automatically processes it so as to maintain a copy of at least one electronic file stored in a source computer.
B. Description of Related Art
A typical modern office uses a number of different databases of information that are frequently updated. Examples of such databases include schedules, contact lists, price lists, real estate lists, and incoming e-mails. Such databases are typically stored as electronic files on either an office-wide server or on individual personal computers located in the office space. Typically, individual workers in the office space are able to use personal computers, usually with network connections, to access the databases. More particularly, the personal computers typically run applications that retrieve the desired information from the databases and display it to the user. With this configuration, the most up-to-date versions of the databases are typically available to the individual workers, even though the electronic database files are frequently updated.
However, many workers often work outside of the office environment at least one day per week, and, typically, it is more difficult to gain access to the most up-to-date versions of important electronic files when outside of the office environment. A currently used solution is to use portable computers to “dial in” to the office network using the PSTN, Internet, or other wireline networks. However, mobile workers do not always have access to wireline connections at all desired times. Accordingly, wireless communications systems have been developed by which mobile workers can access their office databases even without a wireline connection. As an example, some wireless telephones are able to send and receive limited amounts of data using the wireless application protocol (WAP).
However, most of these wireless communications approaches, including the WAP approach, use a “pull” methodology, whereby the user first requests the information and then waits for a response. This “pull” methodology has the disadvantage of high latency and, typically, high cost. The high latency arises from the delay that typically occurs in each step of the process of retrieving the desired information. In particular, there is the time spent entering the keystrokes needed to make the request, the airtime spent transmitting the request, the delay in having the request reaching the office network through intermediate networks, the delay in having the office network search through its databases to formulate a response, and the delay in transmitting the response through the intermediate networks and then over the air interface. The high latency is not only troublesome to the user; it leads to high costs due to the airtime needed to process the request and the response.
The problem becomes more acute the more interactive the transaction becomes. A user using WAP to retrieve a new e-mail message with an attachment provides a simple illustration of the problem. First, the user requests the new e-mail message and receives it after waiting for the latency period described above, for which the user is typically charged airtime. Second, the user reads the new e-mail message and sees that it has an attachment. Then the user must make another request to receive the attachment. The user waits for another latency period to receive it, thereby typically incurring additional airtime charges. Moreover, the latency period may be quite long, because files attached to e-mails are often quite large. Accordingly, existing “pull” approaches, such as WAP have substantial disadvantages.
Another problem with many technologies for receiving data over wireless channels is that they are highly device-specific, i.e., they are based on providing wireless functionality to existing devices, such as specific models of personal digital assistants (PDAs). However, there are a number of problems with device-specific approaches. First, many people use different computing devices at different times, so that providing only one of the user's computing devices with wireless functionality is, at best, only a partial solution. Second, different computing devices differ in their abilities to handle different types of data. For example, desktop PCs typically have much more memory than PDAs, and desktop PCs often have access to high quality monitors, speakers, and peripherals to display information and provide functionality to the user in ways that are unavailable to typical PDAs. On the other hand, PDAs also have many advantages over a desktop PC, such as portability. In addition to the availability of different hardware, different computing devices may have different operating systems and applications available to them. Accordingly, approaches that provide wireless functionality only to specific devices have substantial disadvantages.
For example, Kaufman, U.S. Pat. No. 6,034,621, discloses systems and methods for communicating changes made to a data file on a personal computer (PC) to a personal digital assistant (PDA). In accordance with some of the disclosed embodiments, when the data file on the PC is changed, synchronization information is transmitted over a paging network to a pager that is connected to the PDA, such as by a serial or parallel connection. A synchronization routine in the PDA then interacts with the synchronization information output from the pager to update the data file in the PDA.
While potentially reducing the latency problem, at least for small amounts of data, the Kaufman approach suffers from a number of disadvantages. First, PDAs are not typically on all of the time. Thus, update information may be missed because of the PDA being off. Second, PDAs typically have a very limited memory, i.e., 8 megabytes or less. Because of this limited memory, mobile workers may not be able to access some of the very large electronic files that they can access at their offices.